Why Is It So Bloody Cold And How Long Will It Last?

The Sydney Harbour Brrrrrridge.

Spring may well be just around the corner, but that hasn't stopped record sub-zero temperatures from biting the nation's south-east.

And if you think this morning is cold, (5 degrees in Melbourne and 6.5 degrees in Sydney), that's a lot warmer than Wednesday, when Melbourne woke up to a 0.8-degree-Celsius morning -- the coldest so late in the year since 1957 -- and Sydney recorded its coldest August night in 21 years, at 4.6 degrees.

Bureau of Meteorology forecaster Craig Burke told ten daily the freezing conditions were off the back of a cold front that developed over the weekend.

"We had a cold front that moved across Tasmania and brought snow to low levels, down to 300 metres," he said.

"Then we saw south westerly winds that brought a lot of cold air to Victoria and New South Wales. It was very dry, so we haven't had any more rainfall but it has allowed for some very cold nights."

The weather system brought two consecutive days of cold nights and widespread frost, particularly in the inland areas of Victoria.

READ MORE: Farmers Celebrate Rainfall Across NSW And Queensland

A frost warning was issued for the entire state, with the bureau forecasting "severe" frost would hit the Mallee, Wimmera and East Gipplands districts.

Tullamarine shivered through its coldest low in 32 years of minus two degrees, while Mount Hotham fell to minus 9.8 degrees and Falls Creek hit minus 9.6 degrees.

According to Burke, conditions will be quite mild overnight and will ease into Thursday as an approaching low pressure trough causes wind and cloud to increase, helping most places to stay warm later this week.

"There will be some cold temperatures in The Alps overnight and we'll see some minimum temperatures, but nowhere near as cold further inland in NSW and Victoria," he said.

The fronts might bring windy weather and some rainfall that is expected to hit Victoria on Thursday.

"For New South Wales, there is a possibility we'll see some patchy rain in the west of the state on Friday, but we aren't expecting much," Burke said.

We're having a bumper snow season. Here's Dinner Plain in northeastern Victoria. Image: AAP

It comes after about 10 to 15 millimetres of rain fell across south-eastern Queensland and northern NSW over the weekend, bringing some relief to drought-affected farmers.

"With the weather system that is coming through towards the end of the week, we may get some more patchy rain, but no substantial falls," Burke said.